The difference is this creates a bookmark context menu item that opens up a single bookmarks folder (or sub-menu) that is hilighted.
It opens in a window, and I want to see if I can get it to open it in a new tab instead.

To give you an input for Thunderbird, I currently apply these <a href="data:text/javascript,%2F*%20%3A%3A%3A%3A%3A%3A%3A%3A%20Search%20Toolbar%20Item%20%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%20*%2F%0A%0A(function()%20%7B%0A%09var%20throbber%20%3D%20document.getElementById(%22throbber-box%22)%3B%0A%09var%20searchBox%20%3D%20document.getElementById(%22searchBox%22)%3B%0A%09if%20(!throbber%20%7C%7C%20!searchBox)%0A%09%7B%0A%09%09return%3B%0A%09%7D%0A%09var%20toolbaritem%20%3D%20document.createElement(%22toolbaritem%22)%3B%0A%09throbber.parentNode.insertBefore(toolbaritem%2C%20throbber)%3B%0A%09toolbaritem.appendChild(searchBox)%3B%0A%09toolbaritem.flex%20%3D%203%3B%0A%09searchBox.flex%20%3D%201%3B%0A%7D)()%3B%0A%0A%0A%2F*%20%3A%3A%3A%3A%3A%3A%3A%3A%20Disabled%20Throbber%20%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%20*%2F%0A%0A(function()%20%7B%0A%09var%20throbber%20%3D%20document.getElementById(%22navigator-throbber%22)%3B%0A%09if%20(!throbber)%0A%09%7B%0A%09%09return%3B%0A%09%7D%0A%09throbber.setAttribute(%22disabled%22%2C%20%22true%22)%3B%0A%09throbber.removeAttribute(%22tooltiptext%22)%3B%0A%7D)()%3B%0A%0A%0A%2F*%20%3A%3A%3A%3A%3A%3A%3A%3A%20Select%20Inbox%20on%20Startup%20%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%20*%2F%0A%0Aif%20(!window.arguments%20%7C%7C%20!window.arguments%5B0%5D)%0A%7B%0A%09window.arguments%20%3D%20%5B%22mailbox%3A%2F%2Fnobody%40Local%2520Folders%2FInbox%22%2C%20-1%5D%3B%0A%7D%0A%0A%0A%2F*%20%3A%3A%3A%3A%3A%3A%3A%3A%20No%20New%20Window%20on%20Double%20Click%20%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%3A%20*%2F%0A%0Aeval(%22FolderPaneDoubleClick%20%3D%20%22%20%2B%20FolderPaneDoubleClick.toString().replace(%2Felse%20%7B%5B%5E%7D%5D%2B%7D%2F%2C%20%22%22))%3B%0A">four simple snippets</a> (for the first snippet there's some corresponding <a href="data:text/css,%23mail-toolbar-menubar%20%7B%0A%09border-bottom%3A%200px%20!important%3B%0A%7D%0A%0A%23folderpane_splitter%20%7B%0A%09border-top%3A%200px%20!important%3B%0A%7D%0A%23folderpane_splitter%5Bflatmenu%3D%22true%22%5D%20%7B%0A%09border-top%3A%201px%20solid%20ThreeDShadow%20!important%3B%0A%09border-bottom%3A%201px%20solid%20ThreeDShadow%20!important%3B%0A%7D%0A%0A%23searchBox%20%7B%0A%09border-top%3A%200px%20!important%3B%0A%09height%3A%20auto%20!important%3B%0A%7D%0A%0A%23folderPaneHeader%20%7B%0A%09display%3A%20none%20!important%3B%0A%7D%0A">userChrome.css code</a>).